title: Characterization of the collagenous domain of bovine glomerular basement membrane.
abstract: Bovine glomerular basement membrane was subjected to limited pepsin digestion and the solubilized collagenous polypeptides were characterized. Several electrophoresis systems were used which enabled an examination over a molecular weight range from 20,000 to greater than 10(6). A 0.1% SDS-5% polyacrylamide gel system resolves the reduced digestion product into 17 polypeptides ranging in molecular weight from 78,000 to 340,000. The larger collagenous components were resolved on a 0.1% SDS-2.5% agarose gel system. The nonreduced digestion product resolves into 13 components which vary in molecular weight from 85,000 to 5 million. Upon reduction, the majority of this material is converted to a 165,000 molecular weight component(s) and cross-linked (aldehyde derived) multimers of this component(s) containing as many as 6 cross-linked monomers. The digestion product was subjected to a second pepsin digestion after reduction and alkylation under nondenaturing conditions. This results in a conversion of a larger polypeptides to three lower molecular weight peptides, two of which exhibit an electrophoretic migration identical to alpha 1- and alpha 2-chains of collagen. The results indicate that the collagenous domain of glomerular basement membrane consists of various size collagen molecules connected by disulfide bonds and aldehyde-derived cross-links to form high molecular weight aggregates containing as many as 30 of these polypeptides, and that the larger collagenous polypeptides contain alpha-size segments within their structure.
mesh_terms: D000818:Animals; D001485:Basement Membrane / Q000032:analysis*; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D003094:Collagen / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D066298:In Vitro Techniques; D007678:Kidney Glomerulus / Q000032:analysis*; D008970:Molecular Weight; D010434:Pepsin A / Q000494:pharmacology; D010455:Peptides / Q000032:analysis
chemical_list: D010455:Peptides; D003094:Collagen; D010434:Pepsin A